Vacuum retaining jar

ABSTRACT

A VACUUM RETAINING JAR CONSTRUCTED OF SYNTHETIC PLASTIC MATERIAL HAVING AN INNER SHELL AND AN OUTER SHELL WITH ADJOINING METAL RINGS IMBEDDED IN RESPECTIVE SHELLS AND CONNECTING THE UPPER TERMINAL ENDS OF THE SHELLS IN A PERMANENT AIR-TIGHT RELATIONSHIP. THE OUTER WALL OF THE INNER SHELL AND THE INNER WALL OF THE OUTER SHELL ARE PROVIDED WITH A METALLIC INSULATING COATING. A COVER IS POSITIONED OVER THE JOINT OF THE UPPER ENDS OF THE SHELLS.

Unlted States Patent 1191 1111 3,863,794

Hata 1451 Feb. 4, 1975 VACUUM RETAINING JAR 3,406,857 10/1968 Perry220/9 R Inventor: Hideaki Hath, y Japan FOREIGN PATENTS OR APPLICATIONS73 Assignee; Brighton Corporation Ltd Tokyo, 102,250 8/1963 Norway220/10 Japan 1,525,530 4/1968 France 220/9c 143,907 2/1954 Sweden 220/10[22] Filed: Apr. 11, 1973 [21] Appl. No 350,099 Primary ExaminerHerbertE. Ross [52] U.S. C1. 215/13, 220/9 C ABSTRACT Illt. Cl- 1. A vacuumretaining jar onstructed of ynthetic P135. Field of Search 215/12 R, 13R; 220/9 C, tic material having an inner shell and an outer shell 220/910 with adjoining metal rings imbedded in respective shells andconnecting the upper terminal ends of the References Cited shells in apermanent air-tight relationship. The outer UNITED STATES PATENTS wallof the inner shell and the inner wall of the outer 2,024,065 12/1935Schellens 215/13 R ate Provided with a metallic insulating coatihg- A2,534,295 12/1950 Payson 215/13 R Cover is Positioned Over the joint Ofthe pp ends of 2,880,691 4/1959 the shells. 3,048,294 8/1962 3,225,95412/1965 5 Claims, 3 Drawing Figures VACUUM RETAINING JAR BACKGROUND OFTHE INVENTION This invention relates generally to vacuum jars, and moreparticularly, to an improved synthetic plastic or non-glass dual-shellvacuum jar capable of maintaining a high vacuum over prolonged periodsof time.

Many problems are inherent in the construction of vacuum jars intendedto retain a fluid in as near constant state with as minimum degree ofheat transfer as possible. The most critical of such problems relates tothe construction of the seal between the two vacuumretaining shellmembers most commonly used in such jars. It is known to construct theshells of glass and to seal the shells by heat-fusing them togetherwhile applying a vacuum therebetween. Such glass member jars areextremely fragile and subject to breakage and damage and therefore,while the manner of providing the vacuum seal produces a satisfactoryvacuum, it is applicable to glass jars only.

Vacuum jars constructed of material other than glass are resistant tobreakage and damage and therefore are preferred to glass jars. Suchnon-glass jars do not, however, lend themselves to formation of thevacuum seal by the heat-fusing method useable with glass. The provisionof a non-glass jar constructed of two shells which are tightly sealedtogether to maintain a highly effective vacuum therebetween has longbeen desired but not achieved in the art.

Accordingly, the primary object of this invention is to provide a damageresistant vacuum jar constructed of non-glass material in which thevacuum retaining shell members thereof are connected in tight highlyeffective sealing arrangement so as to maintain the vacuum therebetweenwith a minimum degree of leakage.

Other objects and advantages of the invention will occur to thoseskilled in the art from the ensuing description.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a longitudinal sectional viewtaken through the outer shell of the vacuum retaining jar of theinventron.

FIG. 2 is a similar view taken through the inner shell of the jar.

FIG. 3 is a similar view taken through the assembled vacuum retainingjar of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 3, the vacuumretaining jar constructed in accordance with the invention is designatedJ. There is an inner shell member and an outer shell member 12 which areformed from a suitable synthetic plastic or thermosetting or non-glassmaterial such as a thermoplastic resin which is damage resistant andcapable of being worked per this invention. Each shell member 10, 12 isof generally U-shaped cross-sectional configuration and is provided atthe upper open end thereof with a ring l3, 14, respectively. The rings13 and 14 preferably are formed of stainless steel, but other metals maybe used.

The ring 13 positioned on inner shell 10 has a vertical portion 16extending above the terminal end of the shell 10 and ahorizontally-turned flange 13" on the lower part of the ring 13 which isembedded within the shell around the outer surface thereof. Similarly,ring 14 has a vertical portion 18 extending above the terminal end ofshell 12 and a horizontally-turned flange 14" on the lower part of ring14 is embedded within the shell around the inner surface thereof. Ring13 is formed with a horizontally-disposed rim 13 at the upper end of thevertical portion 16. Ring 14 is formed with a horizontally-disposed rim14 at the upper end of the vertical portion 18. At least part of thevertical portion 16 also is embedded around the outer upper terminal endof shell 10, and at least part of the vertical portion 18 also isembedded around the inner upper terminal end of shell 12.

The outer wall of shell 10 and metal ring 13, and the inner wall ofshell 12 and metal ring 14 are coated with a metallic layer ofapproximately 15 microns thickness to provide continuous insulatinglayers 15 and 19 respectively which are impermeable to air.

Shell member 10 is positioned within shell member 12 to form the vacuumjar .l of FIG. 3. When the inner shell 10 is positioned within outershell 12, rim I3 of ring 13 rests upon rim 14 of ring 14. Having been sopositioned, the juxtaposed surfaces of rims 13', 14' are sealed togetherby weldment, for example, to maintain the two shells 10, 12 in theposition shown in FIG. 3.

In the assembled position, inner shell 10 and outer shell 12 combine toform a vacuum retaining body J having a space 17 therebetween enclosedby the insulating layers 15, 19 which continuously extend over theentire facing surfaces of the shells.

For the purpose of enabling the space 17' to be evacuated to form avacuum therein, a protrusion 20 is formed in the outer lower surface ofshell 12 and a nozzle 22 is inserted within the protrusion connectingspace 17 to atmosphere. A vacuum pump may then be connected to thenozzle to withdraw the air from space 17, and this having been done, thetip of nozzle 22 may be sealed in a known manner.

After shells 10, 12 are assembled as shown in FIG. 3, the upper endsthereof are fitted with a cover member 24 to protect the co-joined rings13, 14 from damage.

The construction of the assembled vacuum retaining jar .l is such thatno part of the plastic surfaces of the opposing walls of inner shell 10and outer shell 12 are exposed to air. This is so because the outerwalls of shell 10 and adjoining ring 13, and the inner walls of shell 12and adjoining ring 14 are completely covered with a metallic coating inthe form of insulating layers 15, 19. The construction is such thatextraneous gas completely is prevented from developing. within the space17 thus ensuring a good inner vacuum retaining body which can maintain ahigh vacuum over prolonged periods of time. Further, by reason of theweldment between rims 13, 14, the seal at the upper ends of shells l0and 12 is air impermeable which ensures against loss of vacuum betweenthe shells.

Since shells l0 and 12 are constructed ofa strong, resistant syntheticplastic resin the vacuum jar J is breakage resistant, unlikeconventional glass jars.

I claim:

1. A vacuum retaining jar comprising:

a. a thermoplastic outer shell;

b. a thermoplastic inner shell positioned therewithin to provide a spacebetween the facing surfaces of the shells, said shells being ofgenerally U-shaped cross-sectional configuration with open upper ends;

c. an annular metal ring provided on the outer surface of the innershell and on the inner surface of the outer shell respectively at theupper ends thereof, said metal rings being partially embedded within therespective shell surfaces so that their outer faces are substantiallyflush with the shell surfaces;

. d. the facing surfaces of the shells and rings being coated with ametallic insulating layer; and

e. said rings having flange means, said flange means being securedtogether to seal the upper ends of the shells and the spacetherebetween.

2. A jar as claimed in claim 1 in which a cover membet is positionedover the upper ends of the shells, said cover member being of generallyUshaped crosssectional configuration.

3. A jar as claimed in claim 1 in which each ring has a vertical portionextending above the terminal open end of the shells and ahorizontally-turned flange on the lower part of each ring extendingradially within the respective shell facing surface.

4. A jar as claimed in claim 3 in whicheach ring has ahorizontally-turned rim formed on the upper part thereof and thesurfaces of the rims are juxtaposed to provide the seal between theshells.

5. A jar as claimed in claim 4 in which the rims are welded together.

